From the Guidelines
The rubella vaccine does not cause miscarriages, and the risk of vaccine-associated malformation is considered negligible. In fact, pregnant women are advised not to receive the rubella vaccine during pregnancy as it contains a live attenuated virus, but this is a precautionary measure rather than due to evidence of harm 1. If a woman inadvertently receives the rubella vaccine during pregnancy, this is not considered a reason to terminate the pregnancy. Studies following thousands of women who were accidentally vaccinated during early pregnancy have not shown an increased risk of birth defects or miscarriages compared to unvaccinated pregnant women 1. The theoretical risk is extremely low, with an estimated risk for serious malformations to fetuses attributable to the mother receiving RA 27/3 vaccine considered to range from zero to 1.6% 1.
Key Points
- The rubella vaccine is not recommended for pregnant women due to the theoretical risk of transmission of the live attenuated virus to the fetus 1.
- However, if a woman inadvertently receives the rubella vaccine during pregnancy, the risk of malformation or miscarriage is considered negligible 1.
- Women are advised to avoid pregnancy for 28 days after receipt of a rubella-containing vaccine as a precautionary measure 1.
- Contracting actual rubella infection during pregnancy, especially in the first trimester, poses a significant risk to the developing fetus, potentially causing congenital rubella syndrome.
- Ensuring immunity to rubella before pregnancy through vaccination is recommended for all women of childbearing age who are not immune.
Recommendations
- Pregnant women who have inadvertently received the rubella vaccine should not consider termination of pregnancy due to the vaccine 1.
- Women of childbearing age who are not immune to rubella should receive the MMR vaccine to prevent congenital rubella syndrome.
- Healthcare providers should counsel women on the risks and benefits of the rubella vaccine and the importance of avoiding pregnancy for 28 days after receipt of the vaccine.
From the Research
Rubella Vaccine and Miscarriage
- The rubella vaccine is designed to prevent congenital rubella syndrome (CRS), which can cause serious consequences, including miscarriage, fetal death, or birth defects, when a pregnant woman is infected with the rubella virus 2, 3.
- Studies have shown that the risk of miscarriage or CRS due to the rubella vaccine itself is negligible or zero 4, 5, 6.
- A systematic review and meta-analysis found no case of vaccine-associated congenital rubella syndrome and estimated a maximum theoretical risk of 1 CRS case in 1008 vaccinated women 5.
- The data suggest that inadvertent vaccination during pregnancy is not an indication for termination of pregnancy, and the risk-benefit balance is in favor of vaccination 5, 6.
- The Centers for Disease Control has maintained a register of women who received rubella vaccine within three months before or after conception and found no abnormalities consistent with congenital rubella syndrome in 144 infants whose susceptible mothers received the RA 27/3 rubella vaccine 6.
Key Findings
- Rubella vaccine can cross the placenta and rarely infect the fetus, but no abnormalities consistent with congenital rubella syndrome have been noted in infants whose susceptible mothers received the vaccine 4, 6.
- The maximum theoretical risk of congenital rubella syndrome-like defects due to the vaccine is estimated to be 1.7% to 2.6% 4, 6.
- Vaccination of nonpregnant postpubertal women who lack serologic proof of immunity or a written record of vaccination can be done safely and effectively 6.
Vaccine Safety
- The available data indicate that if vaccination occurs within three months of conception, the risk is negligible 4.
- Women known to be pregnant should not be vaccinated, and conception should be avoided for three months after vaccination 4.
- The risk of asymptomatic rubella vaccine virus infection of the neonate is estimated to be 1.74% 5.